Composite warren trusses characterized by wood chords and tubular web members have come into wide usage in the western states. The most popular light composite trusses are described in Troutner U.S. Pat. No. 3,137,899 granted June 23, 1964 and Gilb U.S. Pat. No. 3,857,218.
While commercially successful, the Troutner truss embodied in Pat. No. 3,137,899 was limited in the loads it could carry. The limiting factor was the pin joint since high web loads on the metal pin split the wood chord at the pin cross bores.
The Gilb truss U.S. Pat. No. 3,857,218 solved the chord splitting problem and was instantly successful because it raised the load value of the joint substantially.
Because of the Gilb metal edge pin connector, the wood chord was no longer the limiting factor since high test loads caused the webs to fail in the flattened end portions. Further increases in joint values were dependent upon a breakthrough in the web design and a type of metal connector assembly capable of accepting still higher web loads.
Troutner's attempts to raise joint values in trusses with mechanical devices such as his case connected web member Troutner U.S. Pat. No. 3,537,224 were commercially unsuccessful and he has apparently abandoned the metal connector for his recent developments have been in the "re-manufactured wood" field.
Gilb, on the other hand, continued the development of composite trusses using sawn lumber and metal connectors but his efforts shifted to medium and heavy trusses using double lumber members as shown in Gilb, U.S. Pat. No. 3,946,532 granted Mar. 30, 1976. Gilb's efforts to increase design loads in light duty, single sawn lumber chords were unsuccessful until the development of the "Clevis" principle as it is embodied in this application.